Throttle valve for rock drills



March 30 1926.

' 1,573,383 L. C. BAYLES ET AL THROTTLE VALVE FOR ROCK ,DRILLS Filed May 28/ 1925 jeans 13 INVENTOZR.

THE/l? A ORNEY Patented Mar. 30, 1926.

UNITED." sT TEs PATENT OFFICE.

LEWIS G. BAYLES AND FRED M. SLATER, OI EAS'ION, PENNSYLVANIA, ASSIGNORS TO INGEBSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

.'.lIHIRO'JE'JII'JE VALVE FOR ROCK DRILLS.

Application filed May 28,1925. Serial No. 33,321.

To all whom it may concern:

Be it known that we, LEWIS C. Barnes and FRED M. SLATER, citizens of the United States, and residents of Easton, in the county 5 of Northampton and State, of Pennsylvania, have invented a certain Throttle Valve for Rock Drills, of which the following is a specification accompanied by drawmgs.

This invention relates tothrottle valves, but more particularly to throttle valves used in rock drills for controlling the admission of pressure fluid.

' One object of the invention is to prevent accidental turning of the throttle valve.

; Another object is to enable the throttle "valve to be held by mechanical means in limiting and intermediate positions.

- Other objects will appear hereinafter.

* The invention consists of the combinationof elements, features of construction and arrangement of parts having the general mode of operation substantially as hereinafter described and more particularly 5 pointed out in the appended claims and illustrated in' the accompanying drawings,

I in which- Figure l is a sectional view in elevation of a head block for a rock drill provided with a throttle valve constructed in accordance with the practice of the invention.

Figure 2 is a transverse sectional view taken through Figure 1 on the line 2-2 looking in the direction of the arrows,

' Figure 3 is .a perspective view of a throttle ratchet, and

Figure 4 is a perspective view of a throttle ratchet ring.

Referring to the drawing, the invention is shown embodied in a rock drill of which only a head block A is shown to illustrate the invention. In this instance, a valve chamber B which is preferably of cylindrical formation extends transversely through the head block and a recess C is formed coaxially with the valve chamber in one side of the head block. Disposed within the chamber B is a throttle valve D having a recess E in one end. Motive fluid is admitted to the recess. E of the throttle valve through a suitable connection F which is held in position by v a nut G screwed into one side of the valve chamber B. In this instance, a supply passage H is formedi'n the head block for supplying pressure fluid to the percussive cylinder (not shown) and is adapted to communicate with the recess E of the throttle valve through a port J formed in the wall of the valve. A passage K leading from the valve chamber provides communication between the recess E of the valve and a feed cylinder (not shown) through a passage L formed through the valve near the inner end of said recess. The port J and the passage L of the valve are so arranged with respect to each other that they may be simultaneously brought to,register with the passages H and K respectively.

In this instance, the valve D is provided with a stem 0 of smaller cross sectional area thus forming the shoulder P at the juncture of the valve and said stem. A bore Q, is formed between the valve chamber B and the recess C and provides a hearing for the stem 0. The outer end B of the stem 0 is preferably of polygonal cross sectional area to receive a throttle lever S, and the throttle lever S 'is held against removal from said stem by a pin T.

In accordance with the present invention, a ratchet ring U is arranged on the stem 0 to engage the polygonal portion R of the valve stem adjacent the handle S, and is provided on its inner surface with a pair of diametrically opposed extensions V on which are. formed teeth W. A ratchet X is arranged slidably upon the stem 0 and carries a pair of diametrically op-- posed lugs X on its periphery to extend slidably into grooves Y formed in the recess C. On one face of the ratchet X are formed teeth Z to cooperate with the teeth W on the ratchet ring U. The teeth Z are in this instance formed in series in opposed arcs to permit the valve to be rotated through a quadrant. A pair of opposed stops 1; are formed on the face carrying the teeth Z and cooperate with the extensions V for limiting rotation of the valve. In order to hold the teeth Z on the ratchet in yieldable engagement with the teeth W o'f-the ring thus preventing accidental turn mg of the valve, a spring a is arranged about the stem 0 and bears with one end against said ratchet; and with the other end against the end wall of the recess C.

To prevent the accumulation of dust Within the recess C, a passage d is formed through the valve D and extends through the stem 0 to communicate at its outer end with the recess C. The passage (Z is so positioned with respect to the passage K in the head block that when the valve is in elosed position the passage d will register with the passage K and provide a means of escape for the pressure fluid in the feed cylinder. The pressure fluid thus escaping, from said cylinder is exhausted into the recess G sand will remove any dust which may have a cumulated in said recess.

The advantages of the present invention reside in the fact that the throttle valve D may be held a'gainst accidental turning in both opened and closed position as well as intermediate positions, and in the manner in which the parts forming the locking .element are protected against the abrading action ofdust which ordinarily causes excessive wear and shortens the life of these forcesthe shoulder P of the the end of the chamber B thus preventing -lll parts. A further advantage resides in the fact that by this arrangement a cylindrical valve may be used, and that the tendency of the valve to stick within-the valve chamber may thus be eliminated. A perfect seal may be obtained at all timessince the valve is constantly exposed to live pressure which valve against the building up of pressure between said shoulder and said end wall. An additional advantage is that when the air is shut off from the valve, the valve will still be held tightly on its seat by the spring 0. a

The above described valve together witl its locking or holding mechanism has been foundto be efiicient in operation, it is inexpensive to manufacture and due to the cleansing action of the pressure fluid permitted to escape into the recess C, the partsor a will be capable of rendering service lon'ger period of time as compared with machines unprovided with this feature.

we claim:

1..In a throttle valve for rock drills, the combinationof a head block, a valve in said head block, a stem carried by said valve, a ratchet ring on said stem, 21 slidable ratchet onthe stem and cooperating with the ratchet ring and the head block for holding the valve in located position, and means on the ratchet and ring to limit rotative movement of the valve.

2. In a throttle valve for rock drills, the combination of a head block, a valve in said head block, a stem carried by said valve, a ratchet ring on said stem to rotate therewith, teeth on said ring, a hollow ratchet .said recess, a valve in said chamber carrymg a stem, a ratchet ring on the stem, a pair of teeth on said ring, a hollow ratchet slidable 011 said stem and having a pair of lugs to cooperate with the grooves in the head block to prevent rotation of the ratchet,

teeth formed on the ratchet to, cooperate with the teeth on the ring for holding the valve in intermediate positions, a spring to hold the teeth on the ratchet ring and the ring in yieldable engagement, and means for limiting rotative movement of the valve.

4. In a throttle Valve for rock "drills, the combination of a head block having a cylindrical chamberand a recess, grooves in said recess, a valve'in said chamber, a stem carried by said valve, a handle on said stem for rotating the valve, a ratchet ring on the stem adjacent the handle, said ratchet ring bein'g adapted to engage the handle to rotate therewith, a pair of diamertically opposed teeth on the ring, a ratchet arranged slidably on the stem and having a pair of diamettrically opposed lugs to register with said grooves for holding the ratchet against rotation, teeth on the ratchet to cooperate with the teeth on the ring for holding the valve in located position, a spring on said stem for holding the teeth on the ratchet and the ring in yieldable engagement, and stops on the ring and ratchet for limiting rotary movement of the valve. I

. In testimony whereof we have signed this specification. I

.LEXVIS C. BAYLES.

FRED M. SLATER. 

